Problems with adherence in adolescents with type 1 diabetes are common - occurring at rates as high as 93% - and have serious health consequences, including suboptimal glycemic control and risk for later complications. Yet, previous interventions to improve adherence in adolescents with type 1 diabetes have only shown modest to moderate effects, and many have been time-intensive and expensive. Thus, there is a need for novel interventions to improve adherence in adolescents with type 1 diabetes. Increasing positive affect (e.g., feeling happy, cheerful, proud) has been shown to promote adherence to treatment recommendations in adult populations. We propose to develop, revise, and pilot test a positive psychology intervention for adolescents with type 1 diabetes aimed at increasing motivation for adherence. This innovative intervention would induce positive affect in adolescents (age 13-17) through tailored exercises in gratitude, self-affirmation, small gifts, and parent affirmations to promote adherence. Specifically, we aim to increase the frequency of blood glucose monitoring, which is one of the best indicators of adherence and is strongly linked to glycemic control. We will also explore the use of technology, by developing and comparing telephone-administered vs. automated text- messaging versions of the intervention, to determine which mode of delivery is more appealing and convenient for adolescents. The study will be conducted by a multidisciplinary team, consisting of Sarah Jaser, PhD, a pediatric psychologist, and two collaborators, Robin Whittemore, PhD, APRN, a nurse researcher, and Stuart Weinzimer, MD, a pediatric endocrinologist. We believe that this low-cost positive psychology intervention has the potential to increase adolescents' motivation for performing blood glucose monitoring without adding to the burden of treatment management. Results from the proposed study will provide the basis for a large scale randomized clinical trial of the intervention.